Table of Contents
Sub drilling rig is a complex set of elements. A semi-submersible drill rig is a set of elements having its own purpose.
Types of the semi-submersible drilling rigs
A huge range of equipment, which is represented by models of domestic and foreign production allows to group semi-submersible drilling rigs in many ways. The most commonly used classification criteria are:
- drilling technique
- type of machine operation
- type of equipment drive
- the depth of drilled wells
- way of moving
- the location of the device.
Classification of semisubmersible drilling rigs by drilling method
Based on this indicator, the following types of submersible drilling rigs are selected for drilling wells:
- Machines for rotary drilling. Submersible drilling rig makes a hole and destroys the ground with a special tool. It rotates and fits snugly. This technique is used for shallow drilling.
- Machines for rotary-percussive drilling. Submersible rig acts on the ground or rock by hitting the tool, which constantly rotates. The device of this type can be used for drilling wells up to 2,000 meters deep.
- Technique for percussive drilling. It works on the basis of a falling projectile. The impact-drilling device is used for making holes in loose and soft rocks, in hard soils. The system can work not deeper than 100 meters.
- Submersible rigs with vibratory drilling. The breaker is equipped with a column of drill pipes. A vibratory load is transmitted through it. The generator of vibration is a surface device, and the main element of the system is a vibro-sound. Such machines can be used only when drilling rocks that are subjected to physical compaction.
- Equipment for fire-jet drilling. The machine destroys the rock and makes a well with gas jets of high temperatures. Fire flows move with the speed of sound and are generated in the depths of a special burner. Devices of this kind are used for soil and rocks with a crystalline base.
- Equipment for discharge-impulse drilling. Machines affect the ground with electrical discharges and can only be used for deep compaction of rocks.
Classification by installation location
Ground-based technique is installed on a hard ground. Marine devices are equipped with a special platform for surface mounting and supports for the underwater bottom. These two types of drilling rig are mostly used to drill oil and gas wells.